Eight queens n Queens

Refer to the correspondents playing the Blue Bridge Cup If you invade or delete
All codes are similar to those of the original blogger I feel that the array is set too much, and I want to change the code
Wrote a set At first, the function simply thought Set each array element to 0 1 that will do I found something wrong after running Later, it was found that the array elements can be set +=x As long as it is in the same row or diagonal line +1 If multiple conditions are met, it will increase Only when The array element is 0 by 0 It will be considered as the place where the queen can be placed

#include <iostream>
using namespace std;
int map[11][11];
int a[10]; // a[] Store solution 
int n;      // Chessboard size 
int ans;

bool check(int i, int j) // Check (i,j) Is it legal 
{
    
    if (!map[i][j])
        return true; // b[j],c[i-j+n],d[i+j] by 0 This indicates that this point can be used to place chess pieces .
    return false;
}
void set(int i, int j, int x)
{
    
    for (int z = 1; z <= n; z++)
    {
    
        map[z][j] += x;
        map[i][z] += x;
    }
    for (int z = 1; z <= n; z++)
    {
    
        if (i + z <= n && j + z <= n)
        {
    
            map[i + z][j + z] += x;
        }
        if (i + z <= n && j - z >= 1)
        {
    
            map[i + z][j - z] += x;
        }
        if (i - z >= 1 && j + z <= n)
        {
    
            map[i - z][j + z] += x;
        }
        if (i - z >= 1 && j - z >= 1)
        {
    
            map[i - z][j - z] += x;
        }
    }
}
void dfs(int i) // dfs The first i Row chess pieces 
{
                   // The boundary conditions 
    if (i > n)  // dfs Finish all the pieces 
    {
    ;
        ans++;
        if (ans <= 3) // Just the first three solutions 
        {
    
            for (int i = 1; i <= n; i++) // Output solution 
            {
    
                cout << a[i] << ' ';
            }
            cout << endl;
        }
        return;
    }

    for (int j = 1; j <= n; j++) // Enumerate all positions of a row 
    {
                                //(i,j) Points meet the conditions for putting chess pieces , Let's put the pieces on (i,j) spot 
        if (check(i, j))
        {
    
            a[i] = j; // The column number satisfying the solution exists a[i] in 
            set(i, j, 1);
            dfs(i + 1); // Handle the pieces in the next line 
            set(i, j, -1);
        }
    }
}
int main()
{
    
    cin >> n;
    dfs(1);
    cout << ans << endl;
    return 0;
}